This project is designed to examine closely the relationships between four phenomena that contribute risk for delinquent behavior: (1)childhood Conduct Disorder (CD), (2)Attention-Deficit Disorder with Hyperactivity(ADD-H), (3)neuropsychological deficits, and (4)family factors (demographic disadvantage, parental criminality, family disruption and instability, child-rearing and communication styles). The conceptual emphasis is on understanding the influence of these factors on the developmental course of persistent serious delinquent behavior. ADD+CD comorbidity has recently been identified as a strong predictor of later recidivistic criminal offending. The PI's previous research into neuropsychological status and self-reported delinquency has shown that cases with early histories of ADD-H and CD may also show marked deficits in auditory memory and verbal cognitive abilities, and that the delinquent acts of this sub-group are especially aggressive. The proposed research suggests a neuropsychological study of the 500 members of the 4th grade cohort currently being studied longitudinally by the Pittsburgh Youth Study. One-half of the subjects were selected as high risk for delinquency because of symptoms of ADD-H & CD. The PYS is collecting detailed family, mental health, and self-report delinquency data at 6-monthly intervals for the cohort from 1987 through 1991, and those data would be made available for our analysis. The proposed research would conduct neuropsychological assessments of the subjects in 1990 when they are 12 & 13 years old, by administering performance measures of language, visual-motor integration, memory, sustained attention, abstract reasoning, and cognitive/behavioral disinhibition. We hypothesize that (1)knowledge of cognitive deficit and childhood behavior problems can add to our ability to prospectively discriminate persistent/serious delinquents, and (2)neuropsychological strengths may help to protect children from delinquency, despite a criminogenic family social environment. Goals of the research are to analyze the specific cognitive deficit patterns shown by some delinquents in greater depth than has been possible in the past, to focus upon subgroups of delinquents defined developmentally by childhood behavior disorder, and to closely examine the multifactorial facets of family life that interact with individual risk factors in affecting delinquency. The longitudinal risk design of the PYS is well-suited to supporting these research goals.